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stm32_radio: Changed the ID3 parsing code. Corrected VBR play time calculation. 

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@397 bbd45198-f89e-11dd-88c7-29a3b14d5316
This commit is contained in:
kyle.hu.gz 2010-02-09 16:48:33 +00:00
parent 3025e3e8b3
commit 49e317efc1
1 changed files with 129 additions and 52 deletions
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183
bsp/stm32_radio/mp3.c
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@ -252,53 +252,37 @@ int mp3_decoder_run(struct mp3_decoder* decoder)
return 0; return 0;
} }
/* get mp3 information */ static int mp3_parse_id3v1(int fd, struct tag_info *info)
void mp3_get_info(const char* filename, struct tag_info* info)
{ {
int fd; lseek(fd, -128, SEEK_END);
char* id3buffer; read(fd, (char *) mp3_fd_buffer, 128);
rt_size_t bytes_read;
int sync_word;
HMP3Decoder decoder;
MP3FrameInfo frame_info;
id3buffer = (char*)&mp3_fd_buffer[0]; /* ID3v1 */
if (filename == RT_NULL || info == RT_NULL) return; if (strncmp("TAG", (char *) mp3_fd_buffer, 3) == 0)
fd = open(filename, O_RDONLY, 0);
if (fd < 0) return; /* can't read file */
/* init decoder */
decoder = MP3InitDecoder();
/* read data */
bytes_read = read(fd, id3buffer, sizeof(mp3_fd_buffer));
/* get frame information */
sync_word = MP3FindSyncWord(id3buffer, bytes_read);
if (sync_word < 0)
{ {
/* can't get sync word */ strncpy(info->title, (char *) mp3_fd_buffer + 3, MIN(30, sizeof(info->title) - 1));
close(fd); strncpy(info->artist, (char *) mp3_fd_buffer + 3 + 30, MIN(30, sizeof(info->artist) - 1));
mp3_decoder_detach(decoder); return 0;
return; }
return -1;
} }
/* get frame information */ static int mp3_parse_id3v2(int fd, struct tag_info *info)
MP3GetNextFrameInfo(decoder, &frame_info, &id3buffer[sync_word]); {
info->bit_rate = frame_info.bitrate; rt_uint32_t p = 0;
info->sampling = frame_info.samprate;
info->duration = lseek(fd, 0, SEEK_END)/ (info->bit_rate / 8); /* second */
if (strncmp("ID3", id3buffer, 4) == 0) lseek(fd, 0, SEEK_SET);
read(fd, (char *) mp3_fd_buffer, sizeof(mp3_fd_buffer));
if (strncmp("ID3", (char *) mp3_fd_buffer, 3) == 0)
{ {
rt_uint32_t tag_size, frame_size, i; rt_uint32_t tag_size, frame_size, i;
rt_uint8_t version_major; rt_uint8_t version_major;
int frame_header_size; int frame_header_size;
tag_size = ((rt_uint32_t)id3buffer[6] << 21)|((rt_uint32_t)id3buffer[7] << 14)|((rt_uint16_t)id3buffer[8] << 7)|id3buffer[9]; tag_size = ((rt_uint32_t) mp3_fd_buffer[6] << 21) | ((rt_uint32_t) mp3_fd_buffer[7] << 14) | ((rt_uint16_t) mp3_fd_buffer[8] << 7) | mp3_fd_buffer[9];
info->data_start = tag_size; info->data_start = tag_size;
version_major = id3buffer[3]; version_major = mp3_fd_buffer[3];
if (version_major >= 3) if (version_major >= 3)
{ {
frame_header_size = 10; frame_header_size = 10;
@ -307,46 +291,139 @@ void mp3_get_info(const char* filename, struct tag_info* info)
{ {
frame_header_size = 6; frame_header_size = 6;
} }
i = 10; i = p = 10;
// iterate through frames // iterate through frames
while (i < MIN(tag_size, sizeof(id3buffer))) while (p < tag_size)
{ {
if (version_major >= 3) if (version_major >= 3)
{ {
frame_size = ((rt_uint32_t)id3buffer[i + 4] << 24)|((rt_uint32_t)id3buffer[i + 5] << 16)|((rt_uint16_t)id3buffer[i + 6] << 8)|id3buffer[i + 7]; frame_size = ((rt_uint32_t) mp3_fd_buffer[i + 4] << 24) | ((rt_uint32_t) mp3_fd_buffer[i + 5] << 16) | ((rt_uint16_t) mp3_fd_buffer[i + 6] << 8) | mp3_fd_buffer[i + 7];
} }
else else
{ {
frame_size = ((rt_uint32_t)id3buffer[i + 3] << 14)|((rt_uint16_t)id3buffer[i + 4] << 7)|id3buffer[i + 5]; frame_size = ((rt_uint32_t) mp3_fd_buffer[i + 3] << 14) | ((rt_uint16_t) mp3_fd_buffer[i + 4] << 7) | mp3_fd_buffer[i + 5];
}
if (i + frame_size + frame_header_size + frame_header_size >= sizeof(mp3_fd_buffer))
{
if (frame_size + frame_header_size > sizeof(mp3_fd_buffer))
{
lseek(fd, p + frame_size + frame_header_size, SEEK_CUR);
read(fd, (char *) mp3_fd_buffer, sizeof(mp3_fd_buffer));
p += frame_size + frame_header_size;
i = 0;
continue;
}
else
{
int r = sizeof(mp3_fd_buffer) - i;
memmove(mp3_fd_buffer, mp3_fd_buffer + i, r);
read(fd, (char *) mp3_fd_buffer + r, i);
i = 0;
}
} }
if (strncmp("TT2", id3buffer + i, 3) == 0 || strncmp("TIT2", id3buffer + i, 4) == 0) if (strncmp("TT2", (char *) mp3_fd_buffer + i, 3) == 0 || strncmp("TIT2", (char *) mp3_fd_buffer + i, 4) == 0)
{ {
strncpy(info->title, id3buffer + i + frame_header_size + 1, MIN(frame_size - 1, sizeof(info->title) - 1)); strncpy(info->title, (char *) mp3_fd_buffer + i + frame_header_size + 1, MIN(frame_size - 1, sizeof(info->title) - 1));
} }
else if (strncmp("TP1", id3buffer + i, 3) == 0 || strncmp("TPE1", id3buffer + i, 4) == 0) else if (strncmp("TP1", (char *) mp3_fd_buffer + i, 3) == 0 || strncmp("TPE1", (char *) mp3_fd_buffer + i, 4) == 0)
{ {
strncpy(info->artist, id3buffer + i + frame_header_size + 1, MIN(frame_size - 1, sizeof(info->artist) - 1)); strncpy(info->artist, (char *) mp3_fd_buffer + i + frame_header_size + 1, MIN(frame_size - 1, sizeof(info->artist) - 1));
} }
p += frame_size + frame_header_size;
i += frame_size + frame_header_size; i += frame_size + frame_header_size;
} }
return 0;
}
return -1;
}
/* get mp3 information */
void mp3_get_info(const char* filename, struct tag_info* info)
{
int fd;
rt_size_t bytes_read;
int sync_word;
HMP3Decoder decoder;
MP3FrameInfo frame_info;
if (filename == RT_NULL || info == RT_NULL) return;
fd = open(filename, O_RDONLY, 0);
if (fd < 0) return; /* can't read file */
/* init decoder */
decoder = MP3InitDecoder();
info->data_start = 0;
/*
* TODO - Add UTF-8 support and fix this.
*
* ID3 v2 is generally useless here, because it
* uses UTF-8 encoding, which we can't handle right now.
* But parsing v2 first is nesessary in order to
* find the correct MP3 frame header location,
* in case of the ID3 v2 tag should be there.
*/
// if (mp3_parse_id3v2(fd, info) < 0)
// {
// // ID3 v2 is not available. Fall back to ID3 v1.
// mp3_parse_id3v1(fd, info);
// }
mp3_parse_id3v2(fd, info);
mp3_parse_id3v1(fd, info);
lseek(fd, info->data_start, SEEK_SET);
bytes_read = read(fd, (char *) mp3_fd_buffer, sizeof(mp3_fd_buffer));
/* get frame information */
sync_word = MP3FindSyncWord(mp3_fd_buffer, bytes_read);
if (sync_word >= 0)
{
rt_uint32_t p;
short samples_per_frame;
/* get frame information */
MP3GetNextFrameInfo(decoder, &frame_info, &mp3_fd_buffer[sync_word]);
// Try to locate the Xing VBR header.
if (frame_info.version == MPEG1)
{
p = frame_info.nChans == 2 ? 32 : 17;
samples_per_frame = 1152;
} }
else else
{ {
lseek(fd, -128, SEEK_END); p = frame_info.nChans == 2 ? 17 : 9;
bytes_read = read(fd, id3buffer, 128); samples_per_frame = 576;
/* ID3v1 */
if (strncmp("TAG", id3buffer, 3) == 0)
{
strncpy(info->title, id3buffer + 3, MIN(30, sizeof(info->title) - 1));
strncpy(info->artist, id3buffer + 3 + 30, MIN(30, sizeof(info->artist) - 1));
} }
p += sync_word + 4;
/* set data start position */ if (strncmp("Xing", (char *) mp3_fd_buffer + p, 4) || strncmp("Info", (char *) mp3_fd_buffer + p, 4))
info->data_start = 0; {
// VBR
if (mp3_fd_buffer[p + 7] & 1 == 1) /* Checks if the frames field exists */
{
rt_uint32_t frames = ((rt_uint32_t) mp3_fd_buffer[p + 8] << 24) | ((rt_uint32_t) mp3_fd_buffer[p + 9] << 16) | ((rt_uint32_t) mp3_fd_buffer[p + 10] << 8) | (rt_uint32_t) mp3_fd_buffer[p + 11];
info->duration = frames * samples_per_frame / frame_info.samprate;
}
}
/*
* There're two other rarely used VBR header standards: VBRI & MLLT.
* I can't find any sample with these headers. So I just ignored them. :)
*/
else
{
// CBR
info->duration = lseek(fd, 0, SEEK_END) / (frame_info.bitrate / 8); /* second */
}
info->bit_rate = frame_info.bitrate;
info->sampling = frame_info.samprate;
} }
/* set current position */ /* set current position */